Free Australian CGT Estimate
Estimate your taxable capital gain and tax payable for a single asset disposal. Values are in AUD.
This is a general estimator only and does not include every ATO rule (small business concessions, non-resident adjustments, partial main residence exemption, indexation pre-1999, or foreign resident withholding).
How this Australia capital gain tax calculator works
In Australia, capital gains tax (CGT) is not a separate tax. Instead, your net capital gain is added to your taxable income and taxed at your normal income tax rate (for individuals), or at the applicable entity rate (for companies and super funds). This calculator estimates your outcome in a practical, step-by-step way:
- Build your cost base from purchase price + eligible costs.
- Calculate your gross capital gain (sale proceeds minus cost base).
- Apply current and carried-forward capital losses.
- Apply the CGT discount if eligible and held at least 12 months.
- Estimate tax payable on the resulting taxable capital gain.
Inputs you should prepare
1) Sale proceeds
The contract sale price, adjusted where needed for ATO market value rules.
2) Cost base items
Your cost base generally includes acquisition price plus costs of acquisition and disposal (for example legal fees, stamp duty, and agent fees), plus capital improvement costs. Keep records and invoices because documentation matters.
3) Capital losses
Capital losses can reduce capital gains but cannot reduce salary or business income. If unused, they carry forward to future years.
4) Holding period and taxpayer type
The 12-month rule is critical. Resident individuals generally receive a 50% discount, eligible SMSFs receive a 33.33% discount, and companies do not receive the CGT discount.
Quick formula (simplified)
Gross Gain = Sale Proceeds − Cost Base
Gain After Losses = Gross Gain − Capital Losses Applied
Taxable Capital Gain = Gain After Losses − CGT Discount
Estimated CGT Tax = Tax with gain − Tax without gain
Example scenario
Suppose you bought an investment asset for $600,000, spent $25,000 on buying costs, $30,000 on capital improvements, and $18,000 on selling costs. You sold for $850,000 and had $10,000 in carried losses.
- Cost base = 600,000 + 25,000 + 30,000 + 18,000 = 673,000
- Gross gain = 850,000 − 673,000 = 177,000
- After losses = 177,000 − 10,000 = 167,000
- If eligible for 50% discount: taxable gain = 83,500
That taxable gain is added to your taxable income and taxed at your relevant rates.
Important Australian CGT points to remember
- Main residence exemption: many owner-occupied homes can be exempt fully or partially.
- Timing: CGT event usually occurs at contract date, not settlement date.
- Discount eligibility: generally requires at least 12 months ownership.
- Capital losses: must be applied before the discount in common scenarios.
- Record keeping: keep purchase, improvement, and sale documents for at least 5 years after relevant CGT events.
What this calculator does not cover
This tool is intentionally simple. It does not model every edge case, including:
- Small business CGT concessions
- Non-resident tax outcomes and withholding rules
- Collectables and personal use assets treatment nuances
- Pre-CGT assets (acquired before 20 September 1985)
- Complex trust distributions and streaming arrangements
Final note
Use this calculator for planning and comparison. Before lodging a tax return or making a sale decision, review ATO guidance or speak with a registered tax agent. A small change in assumptions can materially change your outcome.